What is specific speed of a centrifugal pump?

What is specific speed of a centrifugal pump?

Centrifugal pump impellers have specific speed values ranging from 500 to 10,000 (English units), with radial flow pumps at 500-4000, mixed flow at 2000-8000, and axial flow pumps at 7000-20,000. Values of specific speed less than 500 are associated with positive displacement pumps.

What do you mean by specific speed of pump?

Summary. Specific Speed is a dimensionless rating of pump discharge performance derived from an equation involving shaft speed, flow rate and differential head at a pump’s Best Efficiency Point. It is an important factor used in the design and selection of pumps and impellers.

What is specific speed of pump Quora?

Specific speed is defined as the speed in revolutions per minute at which a geometrically similar impeller would operate if it were of such a size as to deliver 1gpm flow against 1ft head.

How does the specific speed of a centrifugal pump differ from that of a turbine?

The effect of the shape of rotor on specific speed is also similar to that for turbines. That is, radial flow (centrifugal) impellers have the lower values of compared to those of axial-flow designs. Similar to turbines, the higher is the specific speed, the more compact is the machine for given requirements.

Which centrifugal pump has higher specific speed?

The specific speed of an axial flow pump is of the range from 10000 to 20000. From all the values of the specific speed of centrifugal pump, mixed flow pump and axial flow pump, the specific speed of the axial flow pump is the highest.

What is the minimum starting speed of centrifugal pump?

To get the minimum starting speed of a centrifugal pump, it is notice that if the pressure rise in the Impeller is more than or equal to manometric head (Hm) then the centrifugal pump will start to deliver water. Otherwise the pump will not discharge any water, the impeller is rotating.

Which of the following equation can be used for estimation of specific speed ns of centrifugal pump?

N s = N Q H m 3 / 4 Where NS = Specific speed, Q = Discharge, H = Head under which the pump is working, N = Speed at the pump is working.

When the specific speed of the pump is 2600 the type of pump is?

centrifugal pump
Explanation: The specific speed of the pump is given by NS = NQ1/2 / H3/4 and when NS > 2600, the type of pump is centrifugal pump.

What does a high specific speed of a pump imply?

The specific speed of a centrifugal pump is of the range from 500 to 10000. From all the values of the specific speed of centrifugal pump, mixed flow pump and axial flow pump, the specific speed of the axial flow pump is the highest. Thus, the high specific speed of a pump implies that the pump is an axial flow pump.

What is the BEP of a centrifugal pump?

A pump efficiency at the best efficiency point (BEP) depends mainly on the Specific Speed, and a pump with Specific Speed of 1500 is more efficient then the one with specific speed of 1000. How do I increase the centrifugal pump performance? Originally Answered: How do I increase the efficiency of a centrifugal pump?

What is pump specific speed and why is it important?

It allows the use of existing design and test data to design similar higher and lower flow pumps because the specific speed of a pump is independent of its size. As Terry Henshaw stated in “Centrifugal Pump Specific Speed” (Pumps & Systems, September 2011), the definition of specific speed can be confusing.

What is the most important factor in centrifugal pump design?

Many pump designers see specific speed as the most important contributor to centrifugal pump design. It allows the use of existing design and test data to design similar higher and lower flow pumps because the specific speed of a pump is independent of its size.

What is the torque-speed curve of a centrifugal pump?

The torque-speed curve is similar for all centrifugal pumps due to simple math: the pump torque varies as the square of its speed. However, when the pump is at rest—0\% full load speed—the full load torque is never also 0\%. Starting a rotating pump requires the motor to overcome the pump inertia and static friction.